Colloidal and electrophoretic behavior of polymer particulates in suspension

The behavior of individual polymer chains in solvent has been reported in the literature and formed the basis of polymer dynamic understanding [S.R. Quake, H. Babcock and S. Chu, Nature 388 (1997) 151, T.T. Perkins, D.E. Smith and S. Chu, Science 276 (1997) 2016.]. However, thus far, the behavior of isolated particulate polymer or block polymer/copolymers in suspension has not been investigated. In the present work, it is found that classical colloidal theories that describe the particle behavior in suspension can be applied to polymer particulates/blocks. This, in turn, suggests many possibilities in materials processing including co-processing of composites via particulate or powder route to formulate complex microstructures. A polymeric material, polyetheretherketone (PEEK), was used to examine the colloidal behavior of polymer particulates in the present work. Zeta potential of the particulate suspension was measured and the electrostatic interaction of the particulates was examined by DLVO theory. The electrosteric effect between the charged particulates in suspension was also studied. Based on the findings, an optimum condition for a dispersed stable suspension was identified and applied to the electrophoretic deposition of PEEK particulates.